841005850 - SEAT BELTS

SPECIFICATIONS

The vehicle is fitted with seat belts with three mounting points, even for the third rear passenger, with an automatic inertia reel.The seat belts for the front seats, which are height adjustable, are fitted with electrically controlled pretensioners with a load restricter. The seat belt fastening sensors are fitted on the seat belt stalks. This electronic device detects whether the seat belt is fastened and transmits this information to the Air Bag control unit. There is a warning light in the instrument panel for driver''s seat belt only indicating that it is not fastened.The side rear seats have seat belts with pretensioners fitted on the crossmembers under the rear parcel shelf whilst the centre seat has a seat belt on the same crossmember with an inertia reel and three mounting points.

COMPOSITION

Reel with pretensioner and load restricter

The reels for the front and side rear seat belts are fitted with electrically operated pretensioners, controlled by the Air Bag control unit [DF5580C] with a load resricter device. This device, introduced to improve passive safety, is capable of reducing the loads that are normally exerted by the seat belts on the shoulders and the chest following an impact, minimizing the trauma resulting from the effect of the seat belts.

Operation

Section of pretensioners before and after activation

The moment in which a given (sudden) sufficiently serious deceleration of the vehicle takes place, the electronic sensor located in the control unit sents a signal which primes the pyrotechnic charges for the gas generators (5). The combustion of the propellant (6) develops a chemical reaction forming (inert) gas whose pressure produces a force which pushes the rack piston (4) upwards rotating the toothed wheel (1) which is connected to the toothed wheel (2). The later, engaging with the toothed bush (3), changes the rotary movement of the chuck to the opposite direction of the belt winding, rewinding it by a few centimetres.

After any impact that caused the activation of the pretensioner, the seat belt can no longer be used and must be replaced.